Microsoft ASP.NET Core project templates vulnerable to denial of service

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.8 · CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H

EPSS

• CVE-2024-21319: 2.89% estimated exploitation activity in the next 30 days; percentile 86.92 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

A Denial of Service vulnerability exists in ASP.NET Core project templates which utilize JWT-based authentication tokens. This vulnerability allows an unauthenticated client to consume arbitrarily large amounts of server memory, potentially triggering an out-of-memory condition on the server and making the server no longer able to respond to legitimate requests. Announcement Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/290 Mitigation factors This impacts only .NET Core-based projects that were created using any version of project templates listed in affected software. Other project templates e.g., console applications, MAUI applications, Windows Forms or WPF applications, are not affected. Affected software This impacts only .NET Core-based projects that were created using any version of the below project templates. - ASP.NET Core Web App (Model-View-Controller) - ASP.NET Core Web API - ASP.NET Core Web App (Razor Pages) - Blazor Server…

Published by the source

9 Jan 2024, 19:35 UTC

Last modified by the source

4 Jun 2025, 20:19 UTC

Source last checked

26 Oct 2026, 17:03 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-59j7-ghrg-fj52

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# Patch Next advisory brief: CVE-2024-21319

Advisory: Microsoft ASP.NET Core project templates vulnerable to denial of service
IDs: CVE-2024-21319, GHSA-59j7-ghrg-fj52
Record: https://patchnext.com/advisories/cve-2024-21319 (revision 1, source checked 26 Oct 2026, 17:03 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: system.identitymodel.tokens.jwt 7.1.2, 6.34.0, 5.7.0; microsoft.identitymodel.jsonwebtokens 7.1.2, 6.34.0, 5.7.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet system.identitymodel.tokens.jwt: affected < 5.7.0; >= 6.5.0, < 6.34.0; >= 7.0.0-preview, < 7.1.2; fixed in 6.34.0, 7.1.2, 5.7.0
- NuGet microsoft.identitymodel.jsonwebtokens: affected < 5.7.0; >= 6.5.0, < 6.34.0; >= 7.0.0-preview, < 7.1.2; fixed in 6.34.0, 7.1.2, 5.7.0

## Suggested inspection (read-only)
- NuGet system.identitymodel.tokens.jwt: check the installed version with your package manager.
- NuGet microsoft.identitymodel.jsonwebtokens: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on system.identitymodel.tokens.jwt, microsoft.identitymodel.jsonwebtokens.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-59j7-ghrg-fj52 (GitHub-reviewed advisory GHSA-59j7-ghrg-fj52 lists affected ranges: NuGet system.identitymodel.tokens.jwt >=0 =6.5.0 =7.0.0-preview =0 =6.5.0 =7.0.0-preview <7.1.2)

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